Abstract
Recent research has shown that cognitive reserve is associated with better cognitive abilities in ALS/MND, and that a slow brain ageing speed is associated with intact cognition in ALS. This study compares the effects of cognitive reserve and the predicted brain age difference (PAD) on the risk of being diagnosed with ALS, the risk of having cognitive or behavioral impairment, or even fronto-temporal dementia, and on disease duration.Our results indicated that neither PAD nor cognitive reserve was associated with an increased risk of ALS, but that higher PAD was associated with an increased risk of cognitive impairments and FTD, as well as a shortened disease duration. Higher cognitive reserve on the other hand was associated with a lower risk of cognitive impairment and a longer disease duration.Brain age as a proxy of brain reserve influences disease progression and presentation more strongly than cognitive reserve.